zookeeper-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Erdei, Andras" <Andras.Erd...@morganstanley.com>
Subject watcher triggered twice
Date Fri, 26 Feb 2016 14:56:09 GMT
I am using zookeeper 3.4.6:

ZK_INFO@_log_env@717: Client environment:zookeeper.version=zookeeper C client 3.4.6
ZK_INFO@_log_env@728: Client environment:os.name=Linux
ZK_INFO@_log_env@729: Client environment:os.arch=2.6.32-573.3.1.el6.x86_64
ZK_INFO@_log_env@730: Client environment:os.version=#1 SMP Mon Aug 10 09:44:54 EDT 2015

Invoking zoo_awget_children2() with a watcher function, context set to 0x2b75d80019a0:

DSREG_DEBUG@dsreg/Recipe.cc_Context@193: context 0x2b75d80019a0
ZK_DEBUG@_zoo_awget_children2_@2941: Sending request xid=0x56d05cf5 for path [/this/is/a/test]
to ...

The connection is through tcprelay, I take it down, and the watcher gets triggered:

ZK_ERROR@_handle_socket_error_msg@1742: Socket [...] zk retcode=-4, errno=112(Host is down):
failed while receiving a server response
ZK_DEBUG@_handle_error@1234: Calling a watcher for a ZOO_SESSION_EVENT and the state=CONNECTING_STATE
ZK_DEBUG@_process_completions@2132: Calling a watcher for node [], type = -1 event=ZOO_SESSION_EVENT
DSREG_DEBUG@zkcore/Session.cc_dsreg_invoke_recipe_watcher@681: context 0x2b75d80019a0
DSREG_NEVER@zkcore/Session.cc_dsreg_invoke_recipe_watcher@696: Watcher triggered with ztype
ZkSession(-1) zstate Connection to the server has been lost(1) for GlobTracker(0x
1575520)

At this point I delete context 0x2b75d80019a0, wait a bit, then restart tcprelay.  The session
has expired, and the watcher triggers again with the already deleted context 0x2b75d80019a0:

ZK_INFO@_check_events@1724: initiated connection to server [...]
ZK_ERROR@_handle_socket_error_msg@1760: Socket [...] zk retcode=-112, errno=116(Stale file
handle): sessionId=0x1531787c4f70042 has expired.
ZK_DEBUG@_handle_error@1231: Calling a watcher for a ZOO_SESSION_EVENT and the state=ZOO_EXPIRED_SESSION_STATE
ZK_DEBUG@_do_io@446: IO thread terminated
ZK_DEBUG@_process_completions@2132: Calling a watcher for node [], type = -1 event=ZOO_SESSION_EVENT
DSREG_DEBUG@zkcore/Session.cc_dsreg_invoke_recipe_watcher@681: context 0x2b75d80019a0

Is it a bug or feature that the same watcher context gets triggered multiple times?  If it's
a feature, how can I tell when it's safe to delete the context?


Andras



--------------------------------------------------------------------------------

NOTICE: Morgan Stanley is not acting as a municipal advisor and the opinions or views contained
herein are not intended to be, and do not constitute, advice within the meaning of Section
975 of the Dodd-Frank Wall Street Reform and Consumer Protection Act. If you have received
this communication in error, please destroy all electronic and paper copies; do not disclose,
use or act upon the information; and notify the sender immediately. Mistransmission is not
intended to waive confidentiality or privilege. Morgan Stanley reserves the right, to the
extent permitted under applicable law, to monitor electronic communications. This message
is subject to terms available at the following link: http://www.morganstanley.com/disclaimers.
If you cannot access these links, please notify us by reply message and we will send the contents
to you. By messaging with Morgan Stanley you consent to the foregoing.
Mime
View raw message